Sound Insulation Structure for a Garment

ABSTRACT

A sound insulation structure for a garment is disclosed. The sound insulation structure includes a first layer comprising a sound absorbing material, and a second layer configured to be at least one of sound reflecting and sound diffusing.

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates to a sound insulation structure for agarment, a garment comprising a sound insulation structure and a methodof manufacturing a sound insulation structure.

Background Art

Noise is generally perceived as a discomfort in everyday life, inparticular in urban areas. Besides direct damages, especially to theeardrums and to the auditory nerve, noise may also cause mental stress,in particular if suffered for a longer duration. Furthermore, noise maybe distracting and prevent people from relaxing or concentrating onintellectual tasks. This is especially a problem for people doingfitness sports as a means for compensating for professional stress. Forexample, joggers often seek to enjoy tranquility or listen to music viaearphones, both of which may be hindered by an excessive urban noiselevel. Another example is an athlete in a noisy sports hall who wants toprepare mentally for a trial, a match, or a competition.

As a counter measure, noise-cancelling headphones are known in the art.Such headphones record the ambient noise with a microphone and emit aphase-inverted sound signal such that the original ambient sound and thephase-inverted sound signal annihilate at the wearer's ear.

However, noise-cancelling headphones are complex and expensive due toadditional costs in the manufacturing of the noise-cancellingtechnology. Furthermore, noise-cancelling headphones need a batterywhich must be replaced or recharged. Finally, noise-cancellingheadphones, which are often bulky and rather heavy, may not be suitablefor sports activities.

CN203194611U describes a sound insulation garment capable of reducingdamage of noise on the human body. The sound insulation garmentcomprises a garment body provided with a sound insulation componenttherein, and the sound insulation component is a sound insulation liningwhich is fixedly or removably connected with the garment body. When thegarment body includes a cap, the sound insulation lining is arranged inboth the garment body and the cap body.

However, such a sound insulation garment has limitations and may not beable to reduce the noise to an acceptable level. This is especially truefor garments having a hood or cap. A hood or cap may act like a funnelwhich focuses ambient noise entering from the front onto a wearer's eardue to the almost semi-spherical shape of the hood. At the same time,noise may penetrate the hood or cap and from there may reach thewearer's ear without attenuation. The situation may even be worsebecause the cavity formed between the wearer's head and the surroundinghood or cap may act like a resonator and may amplify certain frequenciescausing an opposite and adverse effect.

BRIEF SUMMARY OF THE INVENTION

Although the human ear is sensible to sounds in the frequency range of20 Hz to 20,000 Hz, it is particularly sensible in the frequency rangeof 2,000 Hz to 5,000 Hz.

Therefore, it is an object of the present invention to overcome thetechnical problems mentioned above and to provide a sound insulationstructure for a garment which is easy to manufacture and provides forreduction of the ambient noise, especially when used with a hood or cap.

This problem is solved by a sound insulation structure for a garment,the sound insulation structure comprising at least a first layercomprising a sound absorbing material, and at least a second layerconfigured to be either sound reflecting, sound diffusing, or both.

The second layer may be made sound reflecting, sound diffusing, or both,due to one or more of the following characteristics: its material, thematerial's characteristics, its surface texturing, its shape, etc.

The invention also aims at a sound insulation structure for a garment,the sound insulation structure comprising at least a first materialbeing sound absorbing, and at least a second material that is either atleast a sound reflecting material or at least a sound diffusingmaterial.

The invention aims at a sound insulation structure for a garment, thesound insulation structure comprising at least a first material beingsound absorbing, and at least a second material being either soundreflecting, sound diffusing, or both.

The invention more particularly aims at a sound insulation structure fora garment, the sound insulation structure comprising at least a firstportion comprising a sound absorbing material, and at least a secondportion comprising a material being either sound reflecting, sounddiffusing, or both.

The invention aims at a sound insulation structure for a garment, thesound insulation structure comprising at least a first layer comprisinga sound absorbing material, and at least a second layer comprising amaterial being either sound reflecting, sound diffusing, or both.

A material is said to be sound reflecting when, given an impacting soundwave of a given magnitude at a given frequency on the material, at leastpart of the sound wave is reflected by the material.

A material is said to be sound diffusing when, given an impacting soundwave of a given magnitude at a given frequency on the material, at leastpart of the sound wave is reflected by the material in more than onedirection so that the sum of the magnitude of the sound waves reflectedby the material is strictly higher than the magnitude of each sound wavereflected by the material.

A material is said to be sound absorbing when, given an impacting soundwave of a given magnitude at a given frequency on the material, the sumof the magnitude of the sound wave reflected by the material and of themagnitude of the sound wave passing through the material is lower thanthe magnitude of the impacting wave.

The sound insulation structure according to the invention provides forexcellent noise reduction. This is achieved by combining a soundabsorbing layer with a layer which is either sound diffusing, soundreflecting, or both. The sound insulation structure according to theinvention may be integrated in a garment either as separate componentsor in one piece. The sound insulation structure may be added to agarment, for example at the end of or after the manufacturing of thegarment, or the sound insulation structure may be integral with thegarment and form at least part of the garment.

The first layer comprising the sound absorbing material absorbs sound ornoise that reaches the first layer. This effect may be achieved by amaterial which transforms sound energy (i.e., a time varying pressurefield) into heat, for example, by a friction process in the first layer.

The second layer comprising the sound reflecting and/or diffusingmaterial in combination with the first layer further reduces sound ornoise reaching the ears of a wearer. A sound reflecting materialreflects the impacting sound waves when they impact the surface of thesound reflecting material. A sound diffusing material diffuses theimpacting sound waves in multiple directions with reduced amplitude whenthey impact its surface.

The first layer comprises a sound absorbing material, i.e., the materialof the first layer is more sound absorbing than the material of thesecond layer. If the second layer comprises a sound reflecting material,then this material is more sound reflecting than the material of thefirst layer. If the second layer comprises a sound diffusing material,then this material is more sound diffusing than the material of thefirst layer. If the second layer comprises a sound reflecting and sounddiffusing material, then this material is more sound reflecting andsound diffusing than the material of the first layer. In the lattercase, the material of the second layer ensures both functions, i.e., itis sound reflecting and sound diffusing at the same time.

The sound insulation structure according to the invention may be usedfor a variety of garments including hats, caps, beanies, headbands, andgarments with hoods, wherein the sound insulation structure may either(1) be arranged at least in part on the garment, (2) be embedded in thegarment, or (3) form at least a layer of the garment. For example, thesound insulation structure may be embedded in or form at least a layerof a hood of a garment.

The sound insulation structure may also be arranged around a pocket of agarment for reducing the noise generated by coins, keys, etc. when thewearer of the garment walks, exercises, or runs, for example. In thiscase, the second layer may comprise a sound reflecting material and maybe arranged toward the inside of the pocket.

The second layer may comprise a material which is either soundreflecting or sound diffusing, or both, i.e., sound reflecting and sounddiffusing. Such properties may be achieved, for example, by thecharacteristics of the material itself or by the shape it was given,i.e., its surface structure. Also, a sound diffusing layer may becreated in the sound absorbing material by giving it a specific surfaceshape.

The material of the first layer and the material of the second layer maybe the same material, with the material having different properties indifferent regions. For example, the material may have a differentdensity, fiber structure, shape, surface texture, etc. in the firstlayer than in the second layer. In particular, the material may have avarying density and/or fiber structure and/or shape and/or surfacetexture, etc., along its thickness, thus forming different layers withdifferent properties. As a result, in the first layer, the material maybe more sound absorbing than in the second layer. On the other hand, thematerial in the second layer may be more sound diffusing and/orreflecting than in the first layer.

Also, the sound insulation structure may present different layers withdifferent properties, be it made by varying the number of layers, and/orby varying the properties of the layers (e.g., thickness, material,material's characteristics, etc.). In particular, a sound insulationstructure according to the invention may comprise more than one soundabsorbing layer in at least a portion. These two or more sound absorbinglayers may overlap. Alternatively or additionally, the thickness of asound absorbing layer may vary along at least one of its other twodimensions.

In a sound insulation structure according to the invention, the firstlayer and the second layer may at least partially overlap. For example,if the sound insulation structure is part of a hood, both layers mayoverlap in the region of the ears to provide for a good attenuation ofambient noise.

In some embodiments, the first layer may be separated from the secondlayer, i.e., first and second layers may be arranged at differentlocations on the garment. In other embodiments, the first layer may atleast partially overlap the second layer. In still other particularembodiments, the first layer and the second layer may entirely coincide.Thus, different arrangements of the first and second layers are possiblewhich may be chosen depending on the type of application.

The material of the first layer may be any sound absorbing material witha high absorbing ratio, such as a foam, a material comprising somepartially-void cavities, or a spacer knit fabric. In the latter case,the spacer knit fabric may be chosen to have good sound absorbingproperties which may be achieved for example by appropriate yarns, inparticular an appropriate material and diameter of one or more spaceryarn(s), and/or by an appropriate knitting technique, and/or byappropriate distance between the two knit fabric surfaces connected bythe spacer yarn(s).

The second layer may be arranged on an outer side of the first layer.The second layer can be directly along the outer surface of the firstlayer, or on the outer surface of the first layer but separated from thefirst layer by one or more other layers. In particular, in someembodiments, the second layer may be arranged on an outer surface of thegarment. For example, the second layer may be of sound reflectingmaterial arranged at least partially above a first layer of soundabsorbing material. In this way, the sound reflecting layer firstreflects as much sound waves away as possible. Then, the sound absorbinglayer absorbs as much of the remaining sound waves as possible. Thecombination of the two layers provides for excellent sound insulationproperties.

The second layer may be configured to be sound reflecting and the soundinsulation structure may further comprise a third layer configured to besound diffusing. In particular, the second layer may comprise a soundreflecting material and the sound insulation structure may furthercomprise a third layer comprising a sound diffusing material. Thematerial of the third layer is understood to be more sound diffusingthan the material of the first layer and the material of the secondlayer. However, the same material could be used for the third layer andthe first layer and/or the second layer with different properties ineach layer. For example, the material may have a different density,fiber structure, shape, surface texture, etc. in the first layer than inthe third layer. Thus, in the first layer, the material may be moresound absorbing than in the third layer. On the other hand, the materialin the third layer may be more sound diffusing than in the first layer.The third layer may for example be a warp knitted layer. The third layermay for example be created in the sound absorbing material by giving thefirst layer made of sound absorbing material a specific surface shapefor diffusing sound, for example a surface having cone-like orpyramid-like shapes.

The third layer may be arranged on an inner surface of the garment. Ifthe sound insulation structure is, for example, arranged on a hood of agarment, then the sound diffusing inner layer avoids or at least reducesthe funnel effect described above by diffusing the impacting sound wavesin all directions instead of focusing them onto the ears of the wearer.Likewise, resonances may be reduced by the sound diffusing inner surfaceof the hood. The hood may additionally comprise a sound reflecting outerlayer which in combination with the sound absorbing first layer mayfurther reduce the noise perceived under the hood.

The material of the first layer and the material of at least said secondlayer may be chosen so as to reduce average sound pressure by at least 3dB at least in the frequency range of 1,000 Hz to 4,000 Hz. Furthermore,the material and the thickness of the first layer and the shape,material and the thickness of at least said second layer may be chosenso as to reduce average sound pressure by least 5 dB at least in thefrequency range of 1,000 Hz to 4,000 Hz in portions where the firstlayer and the second layer overlap. By shape, it is understood that thegeneral shape and/or the surface texturing of the layer may be chosen soas to achieve desired sound reduction.

The material of the first layer and the material of at least said secondlayer may be chosen so as to reduce average sound pressure by at least 5dB at least in the frequency range of 4,000 Hz to 8,000 Hz. Furthermore,the material and the thickness of the first layer and the shape, thematerial and the thickness of at least said second layer may be chosenso as to reduce average sound pressure by least 7 dB at least in thefrequency range of 4,000 Hz to 8,000 Hz in portions where the firstlayer and the second layer overlap. The material and thickness of thefirst layer and the shape, material and thickness of the second layermay be chosen so as to reduce average sound perceived by a wearer of thegarment by 0.5 to 1 sone at least in the frequency range of 4,000 Hz to8,000 Hz in portions where the first layer and the second layer overlap.

In general, in the context of the present invention, a sound insulationstructure for a garment is envisaged, which reduces average soundpressure by at least 3 dB at least in the frequency range of 1,000 Hz to4,000 Hz. The sound insulation structure may reduce average soundpressure by at least 5 dB at least in the frequency range of 1,000 Hz to4,000 Hz.

In the context of the present invention, a sound insulation structurefor a garment is envisaged, which reduces average sound pressure by atleast 3 dB at least in the frequency range of 2,000 Hz to 5,000 Hz. Thesound insulation structure may reduce average sound pressure by at least5 dB at least in the frequency range of 2,000 Hz to 5,000 Hz.

The sound insulation structure may reduce average sound pressure by atleast 5 dB, in particular by at least 8 dB, and in some embodiments byat least 13 dB in the frequency range of 4,000 Hz to 8,000 Hz.

The sound insulation structure may reduce the sound perceived by awearer of the garment by at least 0.3 sones, in particular by 0.5 sonesin the frequency range of 1,000 Hz to 4,000 Hz. The sound insulationstructure may reduce the sound perceived by a wearer of the garment byat least 0.5 sones, in particular by at least 0.7 sones, moreparticularly by at least 0.9 in the frequency range of 4,000 Hz to 8,000Hz.

The sound insulation structure reduces average sound pressure and/orsound perceived by a wearer of the garment at least for sound wavesimpacting the sound insulation structure perpendicular to a surface ofthe sound insulation structure.

The sound insulation structure may have a total thickness of less than30 mm.

In general, in the context of the present invention, a sound insulationstructure for a garment is envisaged having a total thickness of lessthan 30 mm. The total thickness may be less than 20 mm, in particularless than 10 mm, and in some embodiments less than 5 mm, e.g., about 3mm. In particular, these thicknesses may be realized with a soundinsulation structure having the damping characteristics as describedabove.

Furthermore, in the context of the present invention, a sound insulationstructure for a garment is envisaged, which reduces average soundpressure by at least 5 dB at least in the frequency range of 1,000 Hz to4,000 Hz, and/or by at least 5 dB at least in the frequency range of2,000 Hz to 5,000 Hz, and/or by at least 8 dB in the frequency range of4,000 Hz to 8,000 Hz, and which comprises a total thickness of less than30 mm, in particular less than 20 mm, in particular less than 10 mm, andin some embodiments less than 5 mm, e.g., about 3 mm.

The sound insulation structure comprising a total thickness of less than30 mm, in particular less than 20 mm, in particular less than 10 mm, andin some embodiments less than 5 mm, e.g., about 3 mm, may reduce averagesound pressure by at least 8 dB, more particularly by at least 10 dB,and in some embodiments by at least 16 dB at least in the frequencyrange of 4,000 Hz to 20,000 Hz. The sound insulation structurecomprising a total thickness of less than 30 mm, in particular less than20 mm, in particular less than 10 mm, and in some embodiments less than5 mm, e.g., about 3 mm, may reduce average sound pressure by at least 6dB, in particular by at least 10 dB, and in some embodiments by at least15 dB in the human ear range of 20 Hz to 20,000 Hz.

The sound insulation structure comprising a total thickness of less than30 mm, in particular less than 20 mm, in particular less than 10 mm, andin some embodiments less than 5 mm, e.g., about 3 mm, may reduce thesound perceived by a wearer of the garment by at least one sone, moreparticularly by at least two sones. The sound insulation structurecomprising a total thickness of less than 30 mm, in particular less than20 mm, in particular less than 10 mm, and in some embodiments less than5 mm, e.g., about 3 mm, may reduce average sound pressure and/or soundperceived by a wearer of the garment for sound waves impacting the soundinsulation structure perpendicular to a surface of the sound insulationstructure.

Nonetheless, in some particular embodiments, the sound insulationstructure may have a total thickness of more than 30 mm, allowing tofurther improve the sound insulation. Such sound insulation structurecould be placed in a hood for an outdoor jacket for example.

At least one of the layers of the sound insulation structure accordingto the invention may be textured. Surface texturing may be achieved byproviding the surface with a 3D shape. Surface texturing may improve thesound diffusion properties of that layer. The textured layer may becovered by one or more layers. Thus, the textured layer may not bevisible from the outside and/or inside. For example, the first layer maybe sandwiched between two other layers. One of those layers may comprisethe sound reflecting second layer. In addition, the other layer may besound diffusing and be applied on the textured surface of the firstlayer in order to maximize the sound diffusion by the combination ofthis layer and of the first layer's texturing. The surface texturingalso improves sound absorption because an impacting sound wave which isglobally orthogonal to the sound insulation structure is locallyscattered on a larger surface than when impacting a flat surfaceperpendicularly.

The surface texturing may occur on an inner surface, an outer surface,or both surfaces of said textured layer.

The surface texturing may have the shape of organized or unorganizedpyramids, hemispheres, cones, cubes, ridges, etc. The shapes may or maynot all have the same height and/or sizes. Surface texturing may also beprovided by a second layer being a knitted layer. Thus, the knittedlayer forms small holes, a relief of some depth, and/or a certainpattern which increases sound diffusion.

At least one layer may be made from a mesh. A mesh provides for gooddrape qualities and enhanced fit and comfort. If, for example, a meshsound reflecting layer is arranged at the outer surface of a garment,the perforations of the mesh would provide the overall compositematerial with a superior fit. Also, the holes of the mesh, and thecavities it may create by sitting loose on another layer, can improvethe sound diffusion of the sound insulation structure. The material ofthe mesh may also at least partially absorb acoustic waves.

The second layer may be a coating. For example, the sound insulationstructure may comprise a first sound absorbing core layer, wherein thesecond layer is a coating on the core layer. The coating may be arrangedon an outer and/or inner surface of the core layer. Such coating may besound reflecting and/or sound diffusing, thereby forming a second orthird layer on the core layer. Such coating may also be applied on otherlayers of the garment, such as for example on a fabric layer put outsideor inside the sound absorbing layer for esthetic reasons or thermalinsulation.

The first layer and/or the second layer or both may be removable fromthe sound insulation structure. Thus, the first layer and/or the secondlayer may be removably attached to the sound insulation structure. Inone embodiment, the whole sound insulation structure may be removablyattached to the garment. Means for removably attaching the layers and/orthe sound insulation structure may be a hook-and-loop fastener, azipper, a press-stud, or the like.

Alternatively, the first layer may be bonded to at least a second layer.If the sound insulation structure comprises a third layer, the thirdlayer may be bonded to the first layer and/or the second layer. Suchbonding may be obtained by gluing the second layer onto the first layer.Alternatively, the first layer may be attached to at least a secondlayer at spaced intervals, for example, by stitching.

The first layer may be attached to at least a second layer by stitching.The layers of the sound insulation layer may be stitched using a merrowstitch (also called overlock stitch). Such a seam creates a good bondingbetween the layers of such structure. A bonding tape (made from PU orTPU) could be placed over the seam to secure the stitch, to reinforcethe seam, to improve water impermeability, and/or for estheticalreasons.

At least one layer may comprise perforations. In this way, breathabilityof the sound insulation structure and, thus, of the garment may beimproved.

At least a portion of the sound insulation structure may be capable offorming, being embedded in, or being attached to a hood. Thus, thefunnel effect mentioned above may be reduced.

Throughout this disclosure, the average sound reduction in a frequencyrange is understood as an average of the sound reduction values obtainedfor a plurality of frequencies in this frequency range.

The geometry of the sound insulation structure in a hood, the materialand the thickness of the first layer, and the material and the thicknessof at least said second layer may be chosen so as to reduce averagesound pressure by least 5 dB at least in the frequency range of 1,000 Hzto 4,000 Hz, for sound waves toward the back of the hood, toward theside of the hood, and toward the front of the hood, where the opening ofthe hood is the front of the hood. The geometry of the sound insulationstructure in the hood can include the position of the sound insulationstructure in the hood, the shape and sizes of the sound insulationstructure, the structure of the sound insulation structure, and thegeometry of the hood itself.

More particularly, the geometry of the sound insulation structure in thehood, the material and the thickness of the first layer, and thematerial and the thickness of at least said second layer may be chosenso as to reduce average sound pressure by at least:

-   -   5 dB at least in the frequency range of 1,000 Hz to 4,000 Hz,        for sound waves toward the front of the hood, in particular at        least 8 dB, and more particularly 11 dB,    -   5 dB at least in the frequency range of 1,000 Hz to 4,000 Hz,        for sound waves toward the side of the hood, in particular at        least 9 dB, and more particularly 12 dB,    -   5 dB at least in the frequency range of 1,000 Hz to 4,000 Hz,        for sound waves toward the back of the hood, in particular at        least 7 dB, and more particularly 10 dB.

The geometry of the sound insulation structure in the hood, the materialand the thickness of the first layer, and the material and the thicknessof at least said second layer may be chosen so as to reduce averagesound pressure by at least 5 dB at least in the frequency range of 4,000Hz to 8,000 Hz, for sound waves toward the back of the hood, toward theside of the hood, and toward the front of the hood, where the opening ofthe hood is the front of the hood. In particular, the geometry of thesound insulation structure in the hood, the material and the thicknessof the first layer, and the material and the thickness of at least saidsecond layer may be chosen so as to reduce average sound pressure by atleast 7 dB at least in the frequency range of 4,000 Hz to 8,000 Hz forsound waves toward the back of the hood, toward the side of the hood,and toward the front of the hood. More particularly, the geometry of thesound insulation structure in the hood, the material and the thicknessof the first layer, and the material and the thickness of at least saidsecond layer may be chosen so as to reduce average sound pressure by atleast:

-   -   8 dB at least in the frequency range of 4,000 Hz to 8,000 Hz,        for sound waves toward the front of the hood, in particular at        least 10 dB, and more particularly 16 dB,    -   12 dB at least in the frequency range of 4,000 Hz to 8,000 Hz,        for sound waves toward the side of the hood, in particular at        least 16 dB, and more particularly 22 dB,    -   7 dB at least in the frequency range of 4,000 Hz to 8,000 Hz,        for sound waves toward the back of the hood, in particular at        least 10 dB, and more particularly 14 dB.

The hood may be configured so that the distance between the hood and anear of a wearer is at maximum 20 cm. In some embodiments, the distanceis less than 80 mm, and more particularly between 10 mm and 40 mm.

In some embodiments including, for example, hooded garments, but alsohats, beanies, headbands, and caps, the garment may be fit on the earsof the wearer, thereby reducing the distance to 0 mm. The garment may bestretchable so that the garment tightly fits the wearer's head, therebyannihilating the funnel effect. In some embodiments the hood comprisesan inner layer configured to fit on the head of a wearer and an outerlayer sitting loosely around the inner layer—the sound insulationstructure can be in one or the other of these layers or be partly in oneof them and partly in the other one.

The hood may be configured so that the frontal tip of the hood comes tothe forehead of a wearer. The hood may in particular be configured sothat the frontal tip of the hood comes to the forehead of a wearer whenthe head of the wearer touches the back of the hood. In someembodiments, the hood comes down to the eyebrows. Thus, more sound isprevented from entering the hood than when the frontal tip of the hoodcomes down at a higher point. In some embodiments, the hood's tip maycome down lower than the eyebrows (e.g., to the nose) in order tofurther reduce the incoming noise. At the same time as noise is reduced,incoming light and the field of vision is reduced as well, thus helpingthe wearer to concentrate, e.g., on a trial, match, or exercise.

The hood may be configured to enclose at least 220° of the space arounda wearer's head, in particular at least 260°, and more particularly atleast 275°. The covering angle of the hood may be defined from thecenter of the wearer's head and may be defined in a cross sectionalplane perpendicular to the wearer's longitudinal axis (i.e., atransverse plane in an anatomical meaning or horizontal plane). Largecovering angles of the hood help to reduce the amount of sound enteringthe hood when worn.

The hood may comprise means to tighten the opening of the hood. Thispermits to lower the sound entering from the front opening of the hood.The tightening means may be, for example, a draw cord. The cord may bearranged in a tunnel, e.g., sewn on the edge of the hood's opening. Suchan arrangement has a very good effect of lowering the noise and mayprovide for a further average damping of 5 dB to 10 dB for sound in thefrequency range of 4,000 Hz to 8,000 Hz entering from the front of thehood.

The hood may comprise a flap configured to be removably attached to aside of an opening of the hood so as to reduce the opening of the hoodwhen closed. The flap may be formed in one side of the opening of thehood and be removably attachable to an opposite side of the hood.Alternatively, such flap may be removably attachable on both sides ofthe opening of the hood. Reducing the opening of the hood may reduce thesound incoming from the front of the hood. Flaps are perceived ascomfortable and aesthetic. The flap may be closed by attaching it to theopposite side of the hood by means of a hook-and-loop fastener, apress-stud, a magnet, or the like. The flap may be arranged in thebottom of the hood so as to close the opening in front of the neck of awearer. In some embodiments, the flap may be configured to close theopening in front of a chin of a wearer.

A further aspect of the present invention relates to a garmentcomprising a sound insulation structure as described herein and inparticular as described above.

The garment may comprise a hood and the sound insulation structure maybe arranged at least partially on the hood or form the hood. What hasbeen said above with respect to a hood is valid for such an embodimentas well. The garment may be a hat, headband, or beanie as well.

The sound insulation structure may be removably attached to the garment.Means for removably attaching the sound insulation structure may forexample include a hook-and-loop fastener, a press-stud, a zipper, amagnet, and the like.

A sound insulation structure according to the invention may allow somesound frequencies to pass through it with little or no attenuation. Forexample the sound insulation structure may be designed so as to letsounds with frequencies of car horns, or other types of signaling, passthrough.

In some embodiments, the sound insulation structure may be constructedso as to fold and unfold, similarly to an origami. In particular, a hoodcomprising such sound insulation structure may fold and unfold in aplurality of plies.

The sound insulation structure may further comprise an electronicnoise-cancelling means. The electronic noise-cancelling means maycomprise sound recording means which is configured to record ambientsound, and sound emitting means which is configured to emit aphase-inverted sound signal such that the original ambient sound and thephase-inverted sound signal annihilate at an ear of the wearer of thegarment. The sound recording means may comprise a microphone and thesound emitting means may comprise a loudspeaker, a headphone, or anearphone. The noise-cancelling means may be arranged between the firstlayer and the second layer.

A hood according to the invention may also comprise a visor at the frontto create a better fit around the opening. Such visor may be bonded toat least one of the sound insulation layers.

A further aspect of the present invention relates to a sound insulationstructure for a wearable accessory comprising at least a first layercomprising a sound absorbing material, and at least a second layerconfigured to be either sound reflecting, sound diffusing, or both. Thewearable accessory may for example be a bag or backpack. What has beensaid above with respect to the sound insulation structure for a garmentis valid for the sound insulation structure for a wearable accessory aswell.

But, for example in the case of a bag or a backpack, similar to when thesound insulation structure is implemented in a pocket, the layers arearranged so as to reduce the sound going out of the bag, backpack,pocket, etc.

A still further aspect of the present invention relates to a method ofmanufacturing a sound insulation structure for a garment, comprising thesteps of providing at least a first layer comprising a sound absorbingmaterial, providing at least a second layer configured to be eithersound reflecting, sound diffusing, or both, and at least partiallyjoining the first layer and the second layer.

The first layer and the second layer may be joined permanently, e.g., bywelding, sewing, gluing, and the like. Alternatively, the first layerand the second layer may be removably attached to each other, e.g., bymeans of a hook-and-loop fastener, a press stud, a zipper, and the like.The bonding technique of two layers of a sound insulation structureaccording to the invention permit modification of the performance ofsound insulation and may permit modification of the frequencies of soundthat it insulates from.

The first layer and the second layer may also be joined by dropping onelayer in a mold before foam, which forms the other layer, is poured overthe layer in the mold. The foam may thus adhere to the layer previouslylaid in the mold. In particular, a mesh may be laid in the mold, and thefoam poured on the mesh.

The method may further comprise the step of arranging the first layerand the second layer such that the first layer and the second layeroverlap at least partially in the garment.

The second layer may be configured to be sound reflecting, and themethod may further comprise the steps of providing a third layerconfigured to be sound diffusing, and at least partially joining thethird layer and the first layer. In particular, the second layer maycomprise a sound reflecting material, and the method may furthercomprise the steps of providing a third layer comprising a sounddiffusing material, and at least partially joining the third layer andthe first layer.

The method may further comprise the step of molding the second layer,such that it is configured to diffuse sound. In particular the methodmay further comprise the step of molding a material so as to form thesecond layer and so as to be sound diffusing.

The method may further comprise the step of molding the sound absorbingmaterial, such that it diffuses sound on at least one surface. Inparticular, the method may further comprise the step of molding thesound absorbing material to a shape configured to diffuse sound on atleast one surface.

In the context of the present invention, a method of manufacturing asound insulation garment is envisaged, comprising the steps of providinga garment element, and coating a sound reflecting material on thegarment element. The garment may in particular comprise a hood and thesound reflecting material may be coated at least partially on the hood.The sound reflecting material may be coated on a sound absorbing layerof the garment element. The coating may be a spray coating.

The sound insulation structure manufactured by methods as describedherein may be a sound insulation structure as described herein and inparticular as described above. Likewise, the garment for which the soundinsulation structure is suitable may be a garment as described hereinand in particular as described above.

Each layer of a hood according to the invention may be made from one ora plurality of pieces joined together. In particular at least one layerof the hood may be made from at least two pieces joined together, e.g.,by sewing, gluing, or welding. A bonding tape (made, e.g., from PU orTPU) could be placed over the seam between two pieces to reinforce theseam, for esthetical reasons, and/or to improve water impermeability.

Alternatively, the pseudo-semi-spherical shape of the hood can forexample be achieved by appropriately molding each layer to this shape,or by using a 3D manufacturing process like 3D printing, 3D spraying aviscous material, or 3D warp or weft knitting. Such layer would thus bein one piece, with no stitching, which may also improve the soundinsulation of the sound insulation structure, in particular with respectto the sound absorbing layer. Such insulation may also further beimproved, together with the fit and comfort, by using a 3D scan of acustomer's head and customizing the hood's shape to the head of thecustomer.

In a method according to the invention, dots could be applied on asurface of the sound insulation structure and/or on the surface of thegarment in order to increase the sound insulation. In such a method,dots could be printed using a printing nozzle applying dots of a viscousfluid. A sound insulation structure or a garment comprising such dotsmay therefore have a textured surface, which may improve sounddiffusion.

BRIEF DESCRIPTION OF THE DRAWINGS/FIGURES

Aspects of the present invention will be explained in more detail withreference to the accompanying figures in the following. These figuresshow:

FIG. 1 shows an exemplary embodiment of a sound insulation structureaccording to the invention arranged on a hooded garment with cut-awayportions to reveal different layers;

FIG. 2 shows a further exemplary embodiment of a sound insulationstructure according to the invention arranged on a hooded garment;

FIG. 3 shows an exemplary arrangement of a first and a second layeraccording to the invention in a cross-sectional schematic illustration;

FIG. 4 shows an exemplary arrangement of a first, second, and thirdlayer according to the invention in a cross-sectional schematicillustration;

FIG. 5 shows a further exemplary arrangement of a first and a secondlayer according to the invention;

FIG. 6 shows a cross-sectional schematic illustration of a soundinsulation structure according to the invention;

FIG. 7 shows a cross-sectional schematic illustration of a furtherexemplary arrangement of a first, second, and third layer according tothe invention;

FIG. 8 shows a schematic illustration of a sound insulation structureaccording to the invention using a spacer knit;

FIG. 9 shows a cross-sectional schematic illustration of an exemplarythree-dimensional arrangement of a first, second, and third layeraccording to the invention;

FIG. 10 shows a cross-sectional schematic illustration of a furtherexemplary arrangement of a first and a second layer according to theinvention being joined at the periphery; and

FIG. 11 shows a cross-sectional schematic illustration of a furtherexemplary arrangement of a first, second, and third layer according tothe invention, wherein the second layer is textured.

DETAILED DESCRIPTION OF THE INVENTION

In the following, embodiments and variations of the present inventionare described in more detail.

FIG. 1 shows an exemplary embodiment of a sound insulation structure 10for a garment 11. The garment 11 in the exemplary embodiment of FIG. 1is a hooded garment like a tracksuit top. In general, the soundinsulation structure 10 according to the invention may be used for avariety of garments including hats, caps, and beanies. The soundinsulation structure 10 may alternatively or additionally be arrangedaround a pocket of a garment which reduces noise generated by coins,keys, etc. when the wearer of the garment walks, exercises, or runs, forexample.

In the exemplary embodiment of FIG. 1 the sound insulation structure 10is arranged on the hood 12 of the garment 11. The sound insulationstructure 10 comprises a first layer 13 comprising a sound absorbingmaterial. In the exemplary embodiment of FIG. 1, the first layer 13 is acore layer of the hood 12. The first layer 13 comprises a soundabsorbing material, i.e., the material of the first layer 13 is moresound absorbing than the material of the second layer 14 of the soundinsulation structure 10 to be discussed below. The material of the firstlayer 13 may be a foam, a material comprising some partially-voidcavities, a mesh, or a spacer knit fabric. In the latter case, thespacer knit fabric may be chosen to have good sound absorbing propertieswhich may be achieved for example by an appropriate spacer yarn and/orby an appropriate knitting technique.

In the embodiment of FIG. 1, the material of the first layer 13 is apolyurethane foam.

The sound insulation structure 10 also comprises a second layer 14 of asound reflecting material. The sound reflecting material of the secondlayer 14 is more sound reflecting than the material of the first layer13.

The material of the second layer 14 may, for example, be a coatingcoated onto the first layer 13.

The second layer 14 of the sound insulation structure 10 according tothe invention may be obtained by texturing the first layer's surface.Surface texturing may be achieved by providing the surface with a 3Dshape. Surface texturing may improve the sound diffusion properties ofthe sound insulation structure. The textured second layer 14 may becovered by one or more layers. Thus, the textured second layer 14 maynot be visible from the outside and/or inside. For example, the firstlayer 13 and second layer 14 may be sandwiched between two other layers.One of those latter layers may comprise a sound diffusing and/orreflecting layer. The surface texturing may be at an inner surface, anouter surface or both surfaces of the first layer 13. The surfacetexturing may have the shape of pyramids, hemispheres, cubes, etc.Surface texturing may also be provided by a knitted first layer 13.Thus, the knitted layer forms small holes, a relief of some depth and/ora certain pattern which increases sound diffusion.

In the exemplary embodiment of FIG. 1, the second layer 14 is arrangedas an outer layer of the hood 12 of the garment 11 and comprises a soundreflecting material. However, in other embodiments, the second layer 14may comprise a sound diffusing material or a material being both soundreflecting and sound diffusing. Also, in other embodiments, the secondlayer 14 may be arranged as an inner layer of the hood 12, i.e., beneaththe first layer 13 and may be sound reflecting, sound diffusing or both.This may also be advantageous, for example, in applications where thesound generated inside a garment or an accessory must be reduced, suchas in a pocket or in a backpack.

In the exemplary embodiment of FIG. 1, the material of the first layer13 and the material of the second layer 14 are different materials.However, the material of the first layer 13 and the material of thesecond layer 14 may also be the same material. In this case, thematerial may have different properties in each layer. For example, thematerial in the first layer 13 may have a different density, fiberstructure, shape, surface texture, etc. than the material in the secondlayer 14. Thus, in the first layer 13, the material may be more soundabsorbing than in the second layer 14. On the other hand, the materialin the second layer 14 may be more sound diffusing and/or reflectingthan in the first layer 13.

In general, all layers according to the invention may be either madefrom one piece or may be made from different pieces which may beoverlapping or not. For example, two or more pieces of a layer (e.g.,the sound absorbing layer 13) could overlap over the ears of a wearer toincrease sound absorbance. It is also possible that the thickness of alayer varies. For example, a sound absorbing layer 13 could be thickerin the area of the ears of a wearer to increase sound absorbance in thatarea.

In the exemplary embodiment of FIG. 1, the first layer 13 and the secondlayer 14 coincide in their entirety as they are arranged as layers ofthe hood 12. In other embodiments the first layer 13 may be separatedfrom the second layer 14, i.e., both layers may be arranged at differentlocations on the garment 11. In further embodiments, the first layer 13may at least partially overlap the second layer 14. Thus, differentarrangements of the first layer 13 and the second layer 14 are possiblewhich may be chosen depending on the type of application.

In the exemplary embodiment of FIG. 1, the sound insulation structurefurther comprises a third layer 15 comprising a sound diffusingmaterial. The material of the third layer 15 is understood to be moresound diffusing than the material of the first layer 13 and the materialof the second layer 14. In the exemplary embodiment of FIG. 1 differentmaterials were chosen for the first layer 13 and the third layer 15.However, in other embodiments, the same material could be used for thefirst layer 13 and the third layer 15 having different properties ineach layer. For example, the material in the first layer 13 may have adifferent density, fiber structure, shape, surface texture, etc. thanthe material in the third layer 15. Thus, in the first layer 13, thematerial may be more sound absorbing than in the third layer 15. On theother hand, the material in the third layer 15 may be more sounddiffusing than in the first layer 13. The third layer 15 may for examplebe a warp knitted layer. Furthermore, the material of the third layer 15may be a coating on the first layer 13, a coating on the second layer14, or a coating on a further layer of the garment 11.

In the exemplary embodiment of FIG. 1, the sound diffusing inner layer15 avoids or at least reduces the funnel effect described above bydiffusing the impacting sound waves in all directions instead offocusing them onto the ears. Likewise, resonances may be reduced by thesound diffusing inner surface 15 of the hood 12.

Measurements conducted on an exemplary embodiment similar to that ofFIG. 1 have been led. In this embodiment, the hood comprises a firstlayer made of a PU foam with open cells, an inner layer made of a meshwith open holes, and an outer layer made of a mesh with open holes. Thethree layers were stitched together on the edges of the hood. The soundinsulation structure forms the hood and has a total thickness of about 3mm.

For such measurements a mannequin head with a microphone placed on oneof its ears has been placed in a room. In this room two speakers havebeen spaced apart by one meter and placed so as to form an equilateraltriangle with the head of the mannequin. The measurements have beenrepeated with the mannequin looking between the two speakers (in adirection 30 degrees from each speaker, “front” in the table below),with the mannequin looking right from the speakers (in a direction 60degrees from a first speaker and 120 degrees from the other, “right” inthe table below), and with the mannequin looking away from the speakers(in a direction 150 degrees from each speaker, “rear” in the tablebelow). A first series of measurements have been made with nothing onthe mannequin's head, and a second series with said hood placed on themannequin head.

The results of these measurements are provided in tables 1 and 2 below.

TABLE 1 Sound Magnitude Reduction Front Right Rear 1-4 kHz 4-8 kHz 1-4kHz 4-8 kHz 1-4 kHz 4-8 kHz Average 5.0 8.3 5.5 13.3 5.0 7.7 Reduction[dB/20 μPa] Standard 3.4 3.1 4.0 5.1 2.8 2.6 Deviation [dB/20 μPa]Maximum 11.3 16.4 12.1 22.9 10.1 14.3 reduction [dB/20 μPa]

Table 1 shows the average reduction in sound wave magnitude on theindicated frequency range, the standard deviation around this averagefor the set of measurements obtained, and the maximum value in eachfrequency range, for each incoming direction of the sound (front, right,back). The magnitude reduction is measured in decibels, with thereference sound pressure being 20 μPa.

TABLE 2 Sound Loudness Reduction Front Right Rear 1-4 kHz 4-8 kHz 1-4kHz 4-8 kHz 1-4 kHz 4-8 kHz Average 0.36 0.72 0.57 0.97 0.38 0.71Reduction [sone] Standard 0.29 0.15 0.48 0.50 0.21 0.08 Deviation [sone]Maximum 0.86 0.98 0.80 1.62 0.73 0.79 reduction [sone]

Table 2 shows the results of table 1 weighted by a human sensitivity tofrequencies, the result being expressed in sones.

It should be noted that these measurements reflect the properties of anexemplary embodiment of the present invention and are not to beunderstood as limiting.

For example, the material of the first layer 13 and the material of thesecond layer 14 may be chosen so as to reduce average sound pressure byat least 6 dB, at least in the frequency range of 4,000 Hz to 20,000 Hz.

In general, in the context of the present invention, the soundinsulation structure 10 for a garment 11 may reduce average soundpressure by at least 6 dB, at least in the frequency range of 4,000 Hzto 20,000 Hz. The sound insulation structure 10 may reduce average soundpressure by at least 8 dB, more particularly by at least 10 dB, and insome embodiments by at least 16 dB at least in the frequency range of4,000 Hz to 20,000 Hz. The sound insulation structure 10 may reduceaverage sound pressure by at least 6 dB, in particular by at least 10dB, and in some embodiments by at least 15 dB in the human ear range of20 Hz to 20,000 Hz. The sound insulation structure 10 may reduce thesound perceived by a wearer of the garment 11 by at least one sone, moreparticularly by at least two sones. The sound insulation structure 10may reduce average sound pressure and/or sound perceived by a wearer ofthe garment 11 for sound waves impacting the sound insulation structure10 perpendicular to a surface of the sound insulation structure 10.

In general, in the context of the present invention, the soundinsulation structure 10 for a garment 11 may have a total thickness ofless than 30 mm. The total thickness may be less than 20 mm, inparticular less than 10 mm, and in some embodiments less than 5 mm,e.g., about 3 mm. This is in particular true for a sound insulationstructure with damping characteristics according to tables 1 and 2above.

Furthermore, the sound insulation structure 10 for a garment 11 mayreduce average sound pressure by at least 6 dB, at least in thefrequency range of 4,000 Hz to 20,000 Hz and may comprise a totalthickness of less than 30 mm, in particular less than 20 mm, inparticular less than 10 mm, and in some embodiments less than 5 mm,e.g., about 3 mm. The sound insulation structure 10 comprising a totalthickness of less than 30 mm, in particular less than 20 mm, inparticular less than 10 mm, and in some embodiments less than 5 mm,e.g., about 3 mm, may reduce average sound pressure by at least 8 dB,more particularly by at least 10 dB and in some embodiments by at least16 dB, at least in the frequency range of 4,000 Hz to 20,000 Hz. Thesound insulation structure 10 comprising a total thickness of less than30 mm, in particular less than 20 mm, in particular less than 10 mm, andin some embodiments less than 5 mm, e.g., about 3 mm, may reduce averagesound pressure by at least 6 dB, in particular by at least 10 dB, and insome embodiments by at least 15 dB in the human ear range of 20 Hz to20,000 Hz. The sound insulation structure 10 comprising a totalthickness of less than 30 mm, in particular less than 20 mm, inparticular less than 10 mm, and in some embodiments less than 5 mm,e.g., about 3 mm, may reduce the sound perceived by a wearer of thegarment 11 by at least one sone, more particularly by at least twosones. The sound insulation structure 10 comprising a total thickness ofless than 30 mm, in particular less than 20 mm, in particular less than10 mm, and in some embodiments less than 5 mm, e.g., about 3 mm, mayreduce average sound pressure and/or sound perceived by a wearer of thegarment 11 for sound waves impacting the sound insulation structure 10perpendicular to a surface of the sound insulation structure 10.

In the exemplary embodiment of FIG. 1, the first layer 13, the secondlayer 14, and the third layer 15 are permanently attached to each otherand form, together, the sound insulation structure 10 which coincideswith the garment's hood. The layers are stitched together at the edgesof the hood by a merrow (or overlock) stitch. In general, however,different stitches or different joining techniques such as gluing orwelding could be used as well.

However, in other embodiments, the first layer 13 or the second layer 14or both may be removable from the sound insulation structure. The sameis true for the third layer 15. Thus, at least one layer may beremovably attached to the sound insulation structure 10. In oneembodiment, the whole sound insulation structure 10 may be removablyattached to the garment 11. Means for removably attaching the layersand/or the sound insulation structure may be a hook-and-loop fastener, azipper, a press-stud, a zipper, or the like.

In some embodiments, the first layer 13 and/or the second layer 14and/or the third layer 15 (if present) may comprise perforations. Inthis way, breathability of the sound insulation structure and, thus, ofthe garment may be improved. Such perforations may, for example, becreated by loops of a weft or warp knit fabric, by the apertures of amesh, or may be punched out.

In the exemplary embodiment of FIG. 1, the hood 12 may be configured sothat the distance between the hood 12 and an ear of a wearer is atmaximum 20 cm. In some embodiments, the distance is less than 80 mm andmore particularly between 10 mm and 40 mm. In some embodimentsincluding, for example, the hooded garment 11 of FIG. 1, but also hats,beanies, headbands, and caps, the garment 11 may be fit on the ear ofthe wearer, thereby reducing the distance to 0 mm. The garment 11 may bestretchable so that the garment 11 tightly fits the wearer's head. Atleast a layer of said garment may be stretchable to tightly fit thewearer's head.

The hood 12 may be configured so that the frontal tip of the hood comesto the forehead of the wearer. The hood 12 may further be configured sothat the frontal tip of the hood comes to the forehead of a wearer whenthe head of the wearer touches the back of the hood 12. In otherembodiments, the hood comes down to the eyebrows. In furtherembodiments, the hood's tip may come down lower than the eyebrows (e.g.,to the nose) in order to further reduce the incoming noise.

The hood 12 may be configured to enclose at least 220° of the spacearound a wearer's head, in particular at least 260°, and moreparticularly at least 275°. The covering angle of the hood 12 may bedefined from the center of the wearer's head and may be defined in across sectional plane perpendicular to the wearer's longitudinal axis(i.e., a transverse plane in an anatomical meaning or horizontal plane).

The hood 12 may comprise means to tighten the opening of the hood. Thispermits lowering the sound entering from the front opening of the hood.The tightening means may be a draw cord. The cord may be arranged in atunnel, e.g., sewn on the edge of the hood's opening.

The hood 12 may comprise a flap configured to be removably attached tothe other side of an opening of the hood 12 so as to reduce the diameterof the opening of the hood 12. The flap may be attached to the hood 12by means of a hook-and-loop fastener, a press-stud, a magnet, or thelike. The flap may be arranged in the bottom of the hood 12 so as toclose the opening in front of the neck of a wearer. In some embodiments,the flap may be configured to close the opening in front of a chin of awearer.

FIG. 2 shows a further embodiment of a sound insulation structure 10arranged on a hood 12 of a garment 11. In the exemplary embodiment ofFIG. 2, the sound insulation structure 10 comprises a first layer 13being the core layer of the hood 12, i.e., the first layer 13 definesthe shape of the hood 12. The core layer is made from a sound absorbingmaterial. The sound absorbing material is a PU foam with open cells.

As in FIGS. 6 and 7, the sound absorbing material forms the core layerwhich is sound absorbing and an inner layer (i.e., the side of the hood12 facing the head of the wearer) is sound diffusing and soundabsorbing. The inner layer 15 is sound absorbing because it is made ofthe same sound absorbing material as the core layer 13, and it is sounddiffusing because it comprises a textured surface, for example apyramid-shaped surface structure as in FIG. 7. Such a pyramid-shapedsurface structure helps to diffuse incoming sound waves. The inner layer15 is joined to the core layer 13 by stitching both layers at theirrespective edges. However, the layers may be joined at other locationsadditionally or alternatively. Furthermore, other techniques likewelding or gluing could be used as well.

In this embodiment, the core layer 13 and inner layer 15 may bemanufactured by a hot or cold forming process. To this end, foamedmaterial is placed in a mold comprising a surface structurecorresponding to the negative of the surface structure of the innerlayer 15. Then, the material of the core layer 13 and inner layer 15 ispressed under pressure. The resulting material layers are cut to shapeand an outer layer of the hood 12 may be joined to it by sewing, gluing,or welding, or be sprayed on it. An additional inner layer may be addedonto the inner layer 15 to improve its sound diffusing properties and/orto improve the comfort of the wearer. In one embodiment, this innerlayer may be acoustically transparent.

FIG. 3 shows an exemplary arrangement of a first layer 13 and a secondlayer 14 according to the invention. The first layer 13 in this exampleis sound absorbing, whereas the second layer 14 is either sounddiffusing, sound reflecting, or both. The second layer 14 in thisexample is bonded to the first layer 13, for example, by gluing. Thesecond layer 14 may be arranged on an outer surface of the first layer13 to reflect or diffuse ambient noise. In an alternative embodiment,the second layer 14 may be arranged on an inner surface of the firstlayer 13 to help reduce the sound generated inside a garment or bag. Forexample, the garment may comprise a pocket formed by a sound absorbingcore layer 13 and lined on its inner surface by a sound reflecting ordiffusing layer 14. Thus, sound generated by objects carried in thepocket (e.g., coins) is significantly reduced by such an arrangement.Consequently, such an arrangement could be used with a bag, like abackpack, sports bag, etc., as well.

FIG. 4 shows a further exemplary arrangement of a sound absorbing firstlayer 13, a sound reflecting second layer 14, and a sound diffusingthird layer 15. The second layer 14 and the third layer 15 in thisexample are bonded to the first layer 13, for example, by gluing. Thesecond layer 14 could be arranged on an outer surface of a garment andthe third layer 15 could be arranged on an inner surface of a garment.Such an arrangement could be advantageous, for example, with a hoodedgarment, where the sound insulation structure 10 formed by the threelayers 13, 14, and 15 is arranged on the hood or forms at least a partof the hood. In this example, the second layer 14 would reflect ambientnoise, whereas the third layer 15 would diffuse ambient noise enteringthe hood through its opening, thus decreasing the funnel effectdescribed above. It should be noted, however, that in other embodimentsthe arrangement of the second layer 14 and third layer 15 could bereversed, i.e., the second layer 14 could be arranged on an innersurface of the first layer 13 and the third layer 15 could be arrangedon an outer surface of the first layer 13.

FIG. 5 shows a further exemplary embodiment of a sound absorbing firstlayer 13 and a second layer 14 according to the invention. In thisexample, the second layer 14 is sound diffusing. Additionally, thesecond layer 14 comprises holes, three of which are exemplarily denotedwith the reference numeral 51. The second layer 14 may be a mesh, forexample a knit polyester mesh

The first layer 13 and second layer 14 are arranged, such that there isa gap between both layers. This is achieved by a yarn 52 whichinterconnects both layers 13 and 14. However, the yarn 52 does not joinboth layers 13 and 14, such that they would abut, like with a stitch.Instead, the yarn 52 allows for a spaced apart arrangement of bothlayers 13 and 14. This joining of the first layer 13 and second layer 14may provide, in particular, a better comfort for the wearer.

FIG. 6 shows a cross sectional view of a further exemplary embodiment ofa sound insulation structure 10 according to the invention. In thisexample, the sound insulation structure is made from a single material.The material comprises a density gradient in a direction perpendicularto a surface of the sound insulation structure 10. The material has ahigher density on its outer surface 62 than in other portions, therebycreating a sound reflecting layer 14. Thus, the sound reflecting layer14 is formed by high density material. Such density may be reached bydifferent manufacturing processes, such as use of gravity duringmanufacturing to separate two layers, or curing (e.g., by heat), etc.

From this sound reflecting layer 14 the density decreases and acontinuous layer of material forms the sound absorbing layer 13.

A sound diffusing layer 15 is created on the inner face of the soundinsulation structure 10 by a surface texturing of the material. In theexample of FIG. 6, this surface structure is formed by a random sequenceof grooves, three of which are exemplarily denoted by the referencenumeral 61. Other surface texturing could be used as well, such aspyramids, hemispheres, cubes, etc. which could be regular or random. Inaddition to facilitating sound diffusion, surface texturing alsoincreases the flexibility and pliability of the sound insulationstructure 10. The surface texturing can be formed during manufacturingthe sound insulation structure 10, e.g., during molding, or could beformed in a later step, e.g., by cutting, milling, melting, etc.

FIG. 7 shows a further exemplary arrangement of the first layer 13,second layer 14, and third layer 15. In this example, the soundreflecting second layer 14 is bonded to the first sound absorbing layer13, e.g., by gluing. The sound diffusing third layer 15 is made from thesame material as the first sound absorbing layer 13 and formed in thismaterial as a textured area. The texture in this example ispyramid-shaped. In general, other geometries like random or regularhemispheres, cones, cubes, ridges, etc. could be used as well.

FIG. 8 shows a further exemplary arrangement of a first layer 13 and asecond layer 14 according to the invention. In this example the firstsound absorbing layer 13 is realized as a spacer knit. A spacer knit ismanufactured by weft-knitting or warp-knitting at least one spacer yarn81 between two weft-knitted or warp-knitted plies 82 and 83,interconnecting the two plies 82 and 83 while leaving a gap betweenthese two plies, and simultaneously serving as a filler. The spacer yarn81 can comprise the same material as the plies 82 and 83 themselves,e.g., polyester, or another material. The spacer yarn 81 can also be amonofilament which provides the spacer weft-knitted fabric or spacerwarp-knitted fabric with more stability. In the exemplary embodiment ofFIG. 8 the second layer 14 is coated on a ply 83 of the spacer knit.Such a coating may, for example, be provided by spray coating. The gapbetween the two plies 82 and 83 of the spacer knit allows for additionalfrequency-selective noise cancellation, because the gap acts like aresonant filter for sound waves entering the spacer knit. Thus, thefrequency response of the sound absorbing layer 13 can be set by varyingthe distance of the two plies 82 and 83 correspondingly.

FIG. 9 shows a further exemplary arrangement of the first layer 13,second layer 14, and third layer 15. In this example, all three layerscomprise a 3D shape in the form of a zig-zag shape. In general,different shapes could be used as well, such as a sinusoidal orrectangular shape. Such a 3D shape further increases sound diffusion onboth faces of the sound insulation structure 10, but also increasesflexibility and pliability of the whole sound insulation structure 10.

FIG. 10 shows a further exemplary arrangement of the first soundabsorbing layer 13 and the second sound reflecting or diffusing layer14. In this example, the first layer 13 and the second layer 14 are onlyjoined along their periphery. Thus, in other locations the first layer13 and the second layer 14 are allowed to be spaced apart. The gapbetween the first layer 13 and the second layer 14 could be filled forexample by down, foam, or another filler material to increase thermalinsulation. In the example of FIG. 10, both layers are joined by a seam101 which can be sewn either by hand or by a sewing machine. In general,however, other techniques like welding or gluing could be used as well.

FIG. 11 shows a further exemplary embodiment of a sound insulationstructure 10 according to the invention, wherein the second layer 14 isshaped with plies, but not the first layer 13. In the example, thesecond layer 14 comprises a triangular or pyramid shape and is spacedapart from the first layer 13. The shape of the second layer 14 can beobtained by folding the second layer 14 appropriately. Other shapescould be used as well, such as hemispheres, cones, cubes, ridges, etc.In this example, the shaped second layer 14 could be an inner layer oran outer layer of a garment.

In some embodiments, at least one layer may be obtained by a melt-blownprocess. In a melt-blown process, molten filaments emerge from aspinneret, are drawn by a primary air flow, and are broken into staplefibers by eddy currents. A secondary air flow transfers the fibers ontoa substrate. Melt blowing is a very efficient process for producingnon-woven fabrics. The layer may be obtained by blowing fibers onto asubstrate.

More particularly, the first sound-absorbing layer may be obtained by amelt-blown process. In particular, the size and density of the fibersmay be chosen to obtain a high sound absorption in a targeted range offrequencies.

The second layer may be obtained by a post-processing of one face of thenon-woven first layer, for example by application of heat and/orpressure. The second layer may also be obtained by applying heat and/orpressure to a non-woven fabric, which is then combined with the firstlayer.

The substrate may be a three-dimensional shape. Thereby, the non-wovenlayer may be directly formed in a three-dimensional shape of the finalproduct. Thus, no additional forming of the non-woven fabric is requiredas it is directly made to its useful shape. The three-dimensional shapemay, for example, be a shape of a head, a hood, a pocket, etc.

The substrate may have a texture. The non-woven layer thereby adopts anegative texture on its face in contact with the substrate. Such texturemay enhance comfort and/or sound diffusion.

The substrate may comprise a plurality of holes in at least a portion ofits surface and the method may further comprise the step of applying apressure differential to the plurality of holes, so that the fiberstransferred onto the substrate are attracted by the pressuredifferential. This allows compacting the fibers together to obtain amore dense non-woven fabric. In some embodiments, it may also allowcreating a texture on the surface so as to improve its sound diffusion,sound absorption, and/or comfort, in particular with a wide array inwhich the fibers are pulled in the holes of the array so as to formpadded humps on the surface of the non-woven fabric.

The present invention has been described above by way of exemplaryembodiments. Accordingly, the present invention should not be limited byany of the above-described exemplary embodiments, but should be definedonly in accordance with the following claims and their equivalences.Further, when a particular feature, structure, or characteristic isdescribed in connection with an embodiment, it is submitted that it iswithin the knowledge of one skilled in the art to effect such feature,structure, or characteristic in connection with other embodimentswhether or not explicitly described.

What is claimed is:
 1. A sound insulation structure for a garment, thesound insulation structure comprising: a first layer comprising a soundabsorbing material; and a second layer configured to be at least one ofsound reflecting and sound diffusing.
 2. The sound insulation structureof claim 1, wherein the first layer and the second layer at leastpartially overlap.
 3. The sound insulation structure of claim 1, whereinthe second layer is arranged on an outer surface of the garment.
 4. Thesound insulation structure of claim 1, further comprising a third layerconfigured to be sound diffusing, wherein the second layer is configuredto be sound reflecting.
 5. The sound insulation structure of claim 4,wherein the third layer is arranged on an inner surface of the garment.6. The sound insulation structure of claim 1, wherein the first layerand the second layer are configured to reduce average sound perceived bya wearer of the garment by 0.5 to 1 sone in the frequency range of 4,000Hz to 8,000 Hz in portions where the first layer and the second layeroverlap.
 7. The sound insulation structure of claim 1, wherein the soundinsulation structure has a total thickness of less than 30 mm.
 8. Thesound insulation structure of claim 1, wherein the first layer istextured on at least one surface.
 9. The sound insulation structure ofclaim 1, wherein at least one of the first layer and the second layercomprises a mesh.
 10. The sound insulation structure of claim 1, whereinthe second layer is a coating.
 11. The sound insulation structure ofclaim 1, wherein at least one of the first layer and the second layerare removable from the sound insulation structure.
 12. The soundinsulation structure of claim 1, wherein at least a portion of the soundinsulation structure is configured to be part of a hood.
 13. The soundinsulation structure of claim 12, wherein the hood is configured so thatthe distance between the hood and an ear of a wearer is at maximum 20cm.
 14. The sound insulation structure of claim 12, wherein the hoodcomprises a frontal tip, and wherein the frontal tip is configured to bedisposed at a wearer's forehead.
 15. The sound insulation structure ofclaim 12, wherein the hood is configured to enclose at least 220° ofspace around a wearer's head in a horizontal plane at a center of thewearer's head.
 16. The sound insulation structure of claim 12, whereinthe hood comprises a draw cord configured to tighten an opening of thehood.
 17. The sound insulation structure of claim 12, wherein the hoodcomprises a flap removably attached to a side of an opening of the hood,and wherein the flap is configured to reduce an opening of the hood. 18.A garment comprising the sound insulation structure of claim
 1. 19. Thegarment of claim 18, wherein the garment comprises a hood, and whereinthe sound insulation structure is disposed at the hood.
 20. The garmentof claim 18, wherein the garment comprises a hat, a beanie, or aheadband.
 21. The garment of claim 18, wherein the sound insulationstructure is removably attached to the garment.
 22. A sound insulationstructure for a wearable accessory, the sound insulation structurecomprising: a first layer comprising a sound absorbing material; and asecond layer configured to be at least one of sound reflecting and sounddiffusing.
 23. A method of manufacturing a sound insulation structurefor a garment, the method comprising: providing a first layer comprisinga sound absorbing material; providing a second layer configured to be atleast one of sound reflecting and sound diffusing; and at leastpartially joining the first layer and the second layer.
 24. The methodof claim 23, further comprising: arranging the first layer and thesecond layer such that the first layer and the second layer at leastpartially overlap in the garment.
 25. The method of claim 23, furthercomprising: providing a third layer configured to be sound diffusing;and at least partially joining the third layer and the first layer,wherein the second layer is configured to be sound reflecting.
 26. Themethod of claim 23, further comprising: molding the second layer suchthat the second layer is configured to diffuse sound.
 27. The method ofclaim 23, further comprising: molding the sound absorbing material suchthat the sound absorbing material diffuses sound on at least onesurface.